The venous drainage of the upper limb is not only important for the anatomists but also for clinicians. This is so because the procedure of venepuncture requires good knowledge of vascular anatomy in order to promote safety. The superficial and deep venous drainage of the upper arm will be discussed in this article with clinical reference.
Course and Drainage
As a general rule of thumb, there are superficial and deep veins in the body.
The brachial veins are deep veins which share the same name of the arteries they accompany. Other examples include the radial and ulnar in the upper limb, and the femoral and popliteal veins in the lower limb.
These deep veins are known as venae commitantes, and are commonly seen to be in pairs either side of the artery. They are seen tightly adherent to the arteries while dissection. The deep veins frequently anastomose with each other.
The superficial veins are often can be seen under the skin and have their own names e.g. basilic, cephalic in the upper limb.
The brachial vein (deep vein) accompanies the brachial artery in the region of the upper arm. It is formed by the unification of the ulnar and radial veins at the elbow. The basilic vein joins the brachial vein and becomes the axillary vein at the inferior border of teres major. At it its terminal part the axillary vein is joined by the cephalic vein (this vein runs in the deltopectoral groove). At the lateral margin of the first rib axillary vein continues as the subclavian vein.
The subclavian vein then joins the internal jugular vein and is known as the innominate vein, which becomes the brachiocephalic vein/trunk. This large trunk then drains into the superior vena cava and then into the right atrium.
The deep and superficial palmar arches are closely associated with the deep and superficial arterial arches of the hand.
There is in fact a mirroring of the arterial anatomy, therefore the proper digital veins unite and drain into the common digital veins, and these drain into the superficial venous palmar arch.
The palmar metacarpal veins drain into the deep palmar venous arch.
The dorsal metacarpal veins receive communicating branches from the palmar metacarpal veins, which then drain into the radial veins and these drain into the dorsal venous network of the hand. This dorsal venous network then drains via the two superficial veins (cephalic and basilic).
The radial veins- These veins accompany the artery of the same name. In the hand, the deep palmar venous arch drains into the radial vein, and then up to the brachial vein. The radial veins are smaller than the ulnar veins and receive the dorsal metacarpal veins.
The ulnar veins- These veins accompany the artery of the same name. In the hand, the superficial palmar venous arch drains into the ulnar vein. The ulnar veins receive the tributaries of the deep palmar venous arches and also communicate with the superficial veins at the wrist. Once the veins near the elbow, they receive further branches from the anterior and posterior interosseus veins and also have a large communicating branch with the median cubital vein.
The cephalic vein- This vein is so named as it runs superficially, all the way from the hand to the subclavian vein i.e. towards the head or ‘cephalic.’ It drains the lateral aspect of the arm and forearm and also forms communications with the deep venous system.
The basilic vein- This vein runs down the ulnar side of the arm, and also helps in draining the dorsal venous network of the hand. It is shorter then the cephalic vein, and terminates once it joins the brachial vein.
The brachial vein has many perforating branches that drain both the anterior and posterior compartment of the arm. These include such muscles as the three heads of triceps brachii as well as the anterior compartment of the arm i.e. brachialis and biceps brachii. Both the superficial and deep venous system form numerous connections along their course and within each system.
Significant relations of the vein
Within the region of the upper arm, the brachial vein lies very close to a number of important anatomical structures. It is very close but superficial to the brachial artery and also to the median nerve that descends down the centre of the upper arm. The other nerves of the upper limb i.e. the radial and the ulnar also have a nearby relationship with the brachial vein.
The brachial vein is not visible from the surface as covering it is fascia and several layers of muscles cover it. The superficial cephalic and basilic veins are visible and therefore are regarded as good sites for taking blood. The commonest place for blood taking is the median cubital vein, which is a small vein connecting the basilic and cephalic vein in the anterior region of the elbow. In weight lifters the cephalic vein is usually most prominent, as it has a superficial path that extends all the way to the subclavian vein, hence the name ‘cephalic’ meaning to the head due to its undisturbed course.
Venepuncture and Cannulation
Venepuncture is the process of withdrawing blood from a patient’s vein for blood tests. Cannulation is the procedure of placing a small tube into a patient’s arm for the administration of fluids and medication. In order to perform these procedures safely, it is important for the practitioner to have a good knowledge of venous anatomy.
Venepuncture is commonly performed on the median cubital vein, which is a superficial vein that crossed the elbow. Another site commonly used for these procedures is the dorsal venous network of the hand. When venous access is not possible, a central line may be inserted into the subclavian vein. This enables larger volumes of fluid to be administered and also the monitoring of central venous pressure in heart failure patients.